1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, and more particularly, to an image forming apparatus having an automatic document feeding unit so as to successively read documents.
2. Description of the Related Art
An image forming apparatus is an apparatus that prints an image on a printing medium, e.g., paper, according to an input image signal. An image forming apparatus is classified as a printer, a copying machine, a multi-function printer which has multiple functions of printing, copying and scanning, and the like.
A conventional image forming apparatus includes an image reading unit to read image information recorded on a document, an image forming unit mounted under the image reading unit to form an image on a printing medium, e.g., paper, in response to image information read by the image reading unit or image information transferred from an external apparatus, e.g., a computer, and an automatic document feeding unit mounted above the image reading unit to enable the image reading unit to successively read documents.
The image reading unit is pivotally coupled to an upper portion of the image forming unit to enable a user to perform maintenance work on internal devices of the image forming unit. Accordingly, the image reading unit can be rotated to expose a top of the image forming unit as needed. The automatic document feeding unit is pivotally coupled to an upper portion of the image reading unit to enable the image reading unit to read a pile of documents or thick documents. Accordingly, the automatic document feeding unit can be rotated to expose a top of the image reading unit as needed.
However, in the above arrangement such that the image reading unit is pivotally coupled to the upper portion of the image forming unit and the automatic document feeding unit is pivotally coupled to the upper portion of the image reading unit, when exposing the top of the image forming unit by rotating the image reading unit to perform maintenance work on internal devices of the image forming unit, the automatic document feeding unit mounted above the image reading unit may unintentionally rotate by its own weight and collide with another object, for example, a wall of a building, against which the image forming apparatus is installed, thereby being damaged.